There are particle analyzers which analyze particles by detecting fluorescence generated from the particles. Such a particle analyzer mixes a sample containing particles with a fluorescent dye to prepare a measurement specimen, and causes the prepared measurement specimen to flow in a flow cell. The particle analyzer irradiates the flow of the measurement specimen with light, to detect fluorescence generated from each particle. Based on signals obtained through this detection, the particles are classified. In such a particle analyzer, in order to obtain an accurate measurement result, quality control using a quality control standard material is performed.
With the technique according to U.S. Patent Application Publication No. 2007/013906, the place of the abnormality occurring in the particle analyzer is determined by use of a quality control substance which contains: first standard particles to be fluorescence-stained by a first fluorescent dye; and second standard particles which contain a second fluorescent dye in advance and which are substantially not to be stained by the first fluorescent dye. When the measurement result of the second standard particles is outside a reference range, it is determined that abnormality is in the fluorescence detector. In the case where the measurement result of the second standard particle is within the reference range, when the measurement result of the first standard particle is outside a reference range, it is determined that abnormality is in the specimen preparation mechanism. In the case where the measurement result of the first standard particle is smaller than its reference range, and the measurement result of the second standard particle is greater than its reference range, it is determined that abnormality is in the specimen preparation mechanism and in the fluorescence detector.